In subsequent evolution of Code Division Multiple Access (CDMA) network, the interoperation between the CDMA network and Long Term Evolution (LTE) network is one tendency of network development. It is not a simple replacement procedure that the already commercial CDMA network evolves to the LTE network, but the networks have a long period of coexistence. During this period of coexistence, the interconnection and intercommunication of two wireless networks are essential.
One of the requirements of the high rate packet data (HRPD)—LTE interoperation is to support idle handoff of the access terminal from the HRPD to the LTE. In order to support the interoperation between the HRPD and LTE system, a series of protocol processes are defined in the HRPD system, however, in the existing-implementation, specific operation that the access terminal performs the idle handoff from the HRPD to the LTE is not definite, which may cause these protocol processing modules to be unable to work and effectively support the interoperation between the HRPD and the LTE.